Crappy Mileage No Matter What Tune

[TheGreatWhite]

Hey guys I'm back! Crazy year, didn't have much money here lately but started a new job and I'm back! Anyways, I received the Quadzilla for my 01 a year ago for my birthday and I was super excited because for once I'll have custom tunes and I will be able to get out of the <15mpg that I had been getting with my Smarty S03.... Boy was I wrong..... Year later, mileage still sucks. NEVER got above 15mpg, no matter if I ran a tune of my own, or one of Mike's, Me's, nor Drips tunes. I'm at a loss from where to go from here. With my S03 I got 18mpg ONE TIME so I know its possible, but  I've never been able to break that mid 15mpg mark. All I have done motor wise is 100hp DAP VCO injectors with an Airdog 150, and the axles are 3.53s. Recently the TPPS started going out but I doubt that's entirely the issue. Truck doesn't really smoke at all, but depending on what tune I run it'll obviously effect smoke, just mileage ain't going anywhere.

 

History behind the motor as its not stock to my truck: Threw it in 2 years ago after my 53 block had cracked, motor sat for about 6 years. 4 months after getting it reinstalled in my truck I threw new injectors, tubes, and orings into it and thats the only thing thats been done to it within its 234k mile existence and it did bump up the mileage from 12 to 16 pretty regularly. Previously it was in an old mans truck before it totaled a deer out and subsequently the truck, so all the sensors had been sitting dormant for awhile.

 

My question is am I doing something wrong? I've tried to read the datalogs but nothing is out of the ordinary and honestly I don't really know what I'm looking for, so I'll include a 65mph datalog that I took today, kinda a last second deal but I have other logs I can throw in if need be, this is just the latest and the only log I have of the tune I'm running.

 

If someone can help me I'd be in your debt forever, I'm sick of terrible mileage, especially driving 70 miles a day. I'd really appreciate any help I can get, Happy New Years!

 

EDIT: I'm going to throw this consideration in, but should I swap PCM and ECM? I got the set when I got the new motor and just respectively threw them on there with their motor, cause at the time I didn't know better. Seemed that the old PCM and ECM combo got better mileage, probably not though, still food for thought.....

iQuad-2019-12-26-05.49.267182238428847019659.csv

Edited December 27, 2019 by TheGreatWhite

[dripley]

Big tires maybe?

Edited December 27, 2019 by dripley

[hdpwipmonkey]

Brakes dragging 

[TheGreatWhite]

1 hour ago, dripley said:

Big tires maybe?

235/85/16 on the old girl since shes a dually. Same size of tires I've had on it the entire time.

 

26 minutes ago, hdpwipmonkey said:

Brakes dragging 

What's the best way to check this? I've considered this in the past, as when I redid the drums a year ago they were getting pretty hot right after we installed them but afterwards they adjusted, also new calipers and brakes up front which one was dragging on the old calipers and yet, still no change....

[JAG1]

After a run place your hand near the wheel hubs to see if excess heat. You should be able to feel they are only warm not cookin hot. I do this often on long runs. Also in the morning I place the truck in neutral and let it roll too see if all calipers are unstuck. My driveway is slight slope and if it will roll slow I'm good to go.

 

Map sensor comes to mind as well as intake boots and clamps. I think a muddy/ dirty intercooler will also cause poor mileage. I changed differential oils and noted an increase in mileage on a long haul. At a hundred thousand mostly hauling heavy all the time the rear pumpkin oil was pretty dark. I noticed a big difference after changing it.

Edited December 27, 2019 by JAG1

[TheGreatWhite]

2 minutes ago, JAG1 said:

After a run place your hand near the wheel hubs to see if excess heat. You should be able to feel they are only warm not cookin hot. I do this often on long runs. Also in the morning I place the truck in neutral and let it roll too see if all calipers are unstuck. My driveway is slight slope and if it will roll slow I'm good to go.

 

Map sensor comes to mind as well as intake boots and clamps. I think a muddy/ dirty intercooler will also cause poor mileage. I changed differential oils and noted an increase in mileage on a long haul. At a hundred thousand mostly hauling heavy all the time the rear pumpkin oil was pretty dark. I noticed a big difference after changing it.

Now that you say that, the truck will roll pretty easy so the brakes are fine. Like I said the MAP is from factory and would be my next go to issue but seeming how the Quad has a boost fooler, wouldn't that cancel out that probability? I'm not really sure how the boost fooler works if someone would like to shed some light on it. Intake boots and clamps could be it thats a good point, I have one boot with a weak spot but I check it regularly and it is still going with no leaks plus I can pretty easily peg out my boost gauge. Intercooler was cleaned upon reinstall of the motor and I try to keep everything pretty clean. Same fluid all around in axles and tranny (NV4500) as when I hit 18mpg and with the old motor that regularly got ~18.....

 

Thats what miffs me so much, I understand they arent created equal but cmon!

[JAG1]

Okay, while on your creeper (not talking about dripley) look at the intake boot that goes under the drivers battery. There is a small area where part of the sharp edge of the fender can rub a hole in the boot. Many of us have had to take pliers and fold the sharp edge away from rubbing. It is possible the intake suction can pull enough to open a small hole, but when checking by hand, engine off, it may only feel like a soft spot in the boot. Look for any intake leaks by doing an intake vacuum pressure test.

[dripley]

If your MAP sensor was bad you would know it and should have tripped the CEL. Your truck will be gutless with a failed MAP sensor, very noticeable. A boost fooler just intercepts the signal from the MAP sensor and sends a signal to the ECM that so it never sees over 20 psi so it does not set a an overboost code. Tuners have this built into them for the same reason.

 

Funny @JAG1 one mentions the drivers side boot. I just replaced mine yesterday for that very reason. Had to bend part of the fender away as he describes. Mine had penetrated the boot about 20%. But where he lost me is doing a vacuum test on the intake. I have done pressure test by making an adapter to fit the turbo then pressurizing the system to check for leaks. The system should not be under vacuum when running since the engine is turbo charged. Even at idle the turbo puts out a fair amount air. I need to do mine this weekend because I have a boost leak somewhere.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[JAG1]

Thanks dripley for catching that. I don't think sometimes in my desire to help someone. It's obvious its under pressure not vacuum because of what the turbo does. 

[dripley]

1 minute ago, JAG1 said:

Thanks dripley for catching that. I don't think sometimes in my desire to help someone. It's obvious its under pressure not vacuum because of what the turbo does. 

Wood pecker.

[JAG1]

I promise not to drill your house

[Me78569]

Your load is awful high at cruise state.  That tells me it is taking more power than normal for your truck to move down the road at 65.

[TheGreatWhite]

3 hours ago, JAG1 said:

Okay, while on your creeper (not talking about dripley) look at the intake boot that goes under the drivers battery. There is a small area where part of the sharp edge of the fender can rub a hole in the boot. Many of us have had to take pliers and fold the sharp edge away from rubbing. It is possible the intake suction can pull enough to open a small hole, but when checking by hand, engine off, it may only feel like a soft spot in the boot. Look for any intake leaks by doing an intake vacuum pressure test.

Ill check that boot out! I've done vacuum tests before and nothing has ever came of it.

 

2 hours ago, Me78569 said:

Your load is awful high at cruise state.  That tells me it is taking more power than normal for your truck to move down the road at 65.

could it be the flatbed sticks out 8 inches on both sides?? I've brought that up to a couple people and they've dismissed it but being in Kansas it gets pretty darn windy....

Edited December 27, 2019 by TheGreatWhite

[Me78569]

It could be. 

 

Dullies + flat bed surfaces and light bar.

 

If the datalog was taken driving into the wind that would also account for the higher load.  

 

 

[TheGreatWhite]

14 minutes ago, Me78569 said:

It could be. 

 

Dullies + flat bed surfaces and light bar.

 

If the datalog was taken driving into the wind that would also account for the higher load.  

 

 

I don't recall it being windy when I was driving yesterday.... Could it be a tune issue as well?

[dripley]

34 minutes ago, TheGreatWhite said:

Ill check that boot out! I've done vacuum tests before and nothing has ever came of it.

 

could it be the flatbed sticks out 8 inches on both sides?? I've brought that up to a couple people and they've dismissed it but being in Kansas it gets pretty darn windy....

I pressure test is what you need. Pressurize the intake at the turbo and start spraying all the connections and intake with some soapy water. I blew the intake gasket on mine not long ago. Still have one somewhere and a pressure test is in order for me. Thought I found it yesterday on the boot @JAG1 mentioned, but it had not gone completely thru.

[TheGreatWhite]

5 minutes ago, dripley said:

I pressure test is what you need. Pressurize the intake at the turbo and start spraying all the connections and intake with some soapy water. I blew the intake gasket on mine not long ago. Still have one somewhere and a pressure test is in order for me. Thought I found it yesterday on the boot @JAG1 mentioned, but it had not gone completely thru.

Even if I have a leak will I be able to build as much boost as I can? I can peg it pretty easily.

[dripley]

Just now, TheGreatWhite said:

Even if I have a leak will I be able to build as much boost as I can? I can peg it pretty easily.

That is a good sign. Just how high does your gauge go? Mine would peg at 60psi and there is no way I could ever get there with my set up. But if yours only goes to 20 I would not trust it. 

[TheGreatWhite]

6 minutes ago, dripley said:

That is a good sign. Just how high does your gauge go? Mine would peg at 60psi and there is no way I could ever get there with my set up. But if yours only goes to 20 I would not trust it. 

By peg I mean like hit the wastegate (25psi it seems since it's just got a metal dowl in the tube). It's a 35psi gauge from glowshi(f)t.

[dripley]

I was hitting 20 psi on mine with a 3" section of intake gasket blown out. But 30 to 32 used to be my norm. Fixed that but another has arisen and I need to pressure test again. Thought I found it with the inter cooler boot.

 

My first fuel pressure gauge was a GS. Did not last long. It was priced right though.

Edited December 27, 2019 by dripley